This image shows a section of the remains of Kepler's Supernova, the most recent exploding star to be seen in the Milky Way Galaxy. It was first observed 400 years ago when it was thought to be 'a new star'. In fact, it was the the gas and dust from an exploding star, rapidly expanding. These remnants have now reached a diameter of 14 light years wide and are still expanding at 4 million miles per hour.